The pilots of some large aircraft may not be able to easily see the wingtips of their aircraft and may have difficulty discerning whether there is sufficient clearance for a wingtip of their aircraft to pass by an object, especially if the weather is bad or it is nighttime. This reduced visibility may be a factor in several incidents wherein the wingtips of a large aircraft have struck another aircraft or a fixed object during taxi. If such a collision occurs the aircraft will be removed from service until it has been inspected and, if necessary, repaired. The United States National Transportation Safety Board (NTSB) has issued a Safety Recommendation to the Federal Aviation Administration (FAA) for installation of anti-collision aids, such as onboard camera systems, to help pilots with clearance issues during taxi.